A method for welding high-strength alloys, comprising welding an insert between the pieces jointed, is known in the art (SU Inventor's Certificate No. 336111, B 23 K 9/02, 1972).
However, in this case the insert is made of a material having a less strength than that of the material of the welded pieces, resulting in the reduced strength of the welded joint as a whole.
Most closely approaching the present invention is a method for making a welded joint, comprising the steps of resistance welding a thin metal backing of the same metal as that of a filling wire to an edge of one of pieces welded, fitting up a joint, and welding at a constant current of opposite polarity (JP Application No. 58-9779, B 23 K 9/23, published in 1983).
The method permits obtaining high-quality joints in products made of heat-resistant stainless steels and carbon steels. However, there exist a number of structures of maraging steels that could not be welded by the prior art method without cracks.